IP based mobile networks are, for example, WiMAX networks. WiMAX Networks are defined by the WiMAX Forum and are e.g. based on the IEEE 802.16 standards, as mentioned above. The Network Working Group (NWG) of the WiMAX Forum prescribes in their draft specification, among other issues, the network architecture 100 for WiMAX networks as shown in FIG. 1.
According to FIG. 1, each subscriber station (SS) or mobile subscriber station (MS) (also referred to as a terminal hereinafter) is connected, via reference point R1, with an access service network (ASN) being provisioned by a network access provider (NAP). ASNs are divided into a subset of base stations (BS) and a so-called ASN gateway (ASN-GW). The air interface between a SS/MS and a BS may be defined e.g. in the above-referenced IEEE standards.
Via reference point R3, an ASN is connected e.g. with a connectivity service network (CSN) being provisioned by a network service provider (NSP). CSNs support ASNs concerning authentication of SS/MSs, supply the same with IP addresses and provide access to IP-based networks such as the Internet. Since the CSN, to which an MS is connected to via an ASN, is not necessarily the home CSN of the MS, two CSNs may be connected with each other via reference point R5.
There have been approaches directed to WiMAX.
The existing solutions that are available from WiMAX Forum NWG work do not provide any means to inform a WiMAX device (e.g. SS) of the fact that the network is capable of implementing mobility restrictions like only allowing fixed access or nomadic access.
Furthermore, there is no method or procedure available of how to inform a SS or subscriber about the fact that mobility restrictions apply to a specific network, or about further detailed information related to the mobility restrictions applying to the whole network, or to individual SS or subscribers.
In consideration of the above, according to examples of the present invention, methods, apparatuses, a system, a related computer program product and data structures for informing roaming restrictions are provided.
According to an example of the present invention, in a first aspect, this object is for example achieved by a method comprising:
transmitting, after a network entry authentication procedure, between an access network gateway entity and one of a terminal and a serving entity, generated terminal mobility restriction information in the form of at least one text information element comprised in an authentication notification message.
According to further refinements of the example of the present invention as defined under the above first aspect,
the method further comprises generating the authentication notification message comprising the terminal mobility restriction information in the form of the at least one text information element.
According to an example of the present invention, in a second aspect, this object is for example achieved by a method comprising:
receiving, after a network entry authentication procedure, between an access network gateway entity and one of a terminal and a serving entity, terminal mobility restriction information in the form of at least one text information element comprised in an authentication notification message.
According to further refinements of the example of the present invention as defined under the above first and second aspects,
if the transmitting or receiving is performed between the access network gateway entity and the serving entity, at least one of the following applies: the serving entity is situated in one of a home connectivity service network and a local visited connectivity service network, the authentication notification message is carried by one of a remote authentication dial-in user service request and a diameter request, both relating to an access, authorization, and accounting protocol, and the authentication notification message is carried across an R3 interface between the access network gateway entity and the serving entity;
the at least one text information element is constituted by a type-length-value information element;
the at least one type-length-value information element comprises sub information elements relating to at least one of a restriction type, a list of allowed base stations, a list of prohibited base stations, and an allowed location of the terminal;
the authentication notification message is constituted by a extensible authentication protocol notification request message.
According to an example of the present invention, in a third aspect, this object is for example achieved by a method comprising:
transmitting, via network entity management procedures, terminal mobility restriction information in the form of at least one additional leaf node being added to a network entity management object.
According to further refinements of the example of the present invention as defined under the above third aspect,
the method further comprises adding the at least one additional leaf node to the network entity management object.
According to an example of the present invention, in a fourth aspect, this object is for example achieved by a method comprising:
receiving, via network entity management procedures, terminal mobility restriction information in the form of at least one additional leaf node being added to a network entity management object.
According to further refinements of the example of the present invention as defined under the above third and fourth aspects,
the additional leaf node is added to a primary subscriber parameters leaf node of the management object;
the additional leaf node comprises at least one of a status field, a tree occurrence field, a format field and an access type field;
the additional leaf node represents a value indicating one of a mobile restriction, a fixed restriction and a nomadic restriction;
the additional leaf node is added under both a current subscription node and other subscriptions node in the network;
the network entity management object is constituted by a worldwide interoperability for microwave access supplementary management object;
the additional leaf node is further added to at least one of a contractual agreement preference list leaf node and a roaming agreement preference list leaf node;
a second additional leaf node is further added to the additional leaf node of the management object;
the second additional leaf node comprises a mobility restriction and at least one list indicating elements where the mobility restriction is to be applied, the elements being at least one of network access providers, visited network service providers, and base stations;
the network entity management procedures are based on one of an open mobile alliance device management protocol and a technical report 069 protocol;
the method further comprises judging whether an accuracy of the terminal mobility restriction information is insufficient or not, and, if the accuracy is judged to be insufficient, transmitting or receiving, prior to another network entry authentication procedure, second terminal mobility restriction information in the form of one text information element of a fixed length in one of a downlink channel descriptor message, a ranging response message, a terminal basic capability response message or a registration response message.
According to an example of the present invention, in a fifth aspect, this object is for example achieved by an apparatus comprising:
a transmitter configured to transmit, after a network entry authentication procedure, between an access network gateway entity and one of a terminal and a serving entity, generated terminal mobility restriction information in the form of at least one text information element comprised in an authentication notification message.
According to further refinements of the example of the present invention as defined under the above fifth aspect,
the apparatus further comprises a generator configured to generate the authentication notification message comprising the terminal mobility restriction information in the form of the at least one text information element.
According to an example of the present invention, in a sixth aspect, this object is for example achieved by an apparatus comprising:
a receiver configured to receive, after a network entry authentication procedure, between an access network gateway entity and one of a terminal and a serving entity, terminal mobility restriction information in the form of at least one text information element comprised in an authentication notification message.
According to further refinements of the example of the present invention as defined under the above fifth and sixth aspects,
if the transmitter or the receiver is comprised in the access network gateway entity and the serving entity, at least one of the following applies: the serving entity is situated in one of a home connectivity service network and a local visited connectivity service network, the authentication notification message is carried by one of a remote authentication dial-in user service request and a diameter request, both relating to an access, authorization, and accounting protocol, and the authentication notification message is carried across an R3 interface between the access network gateway entity and the serving entity;
the at least one text information element is constituted by a type-length-value information element;
the at least one type-length-value information element comprises sub information elements relating to at least one of a restriction type, a list of allowed base stations, a list of prohibited base stations, and an allowed location of the terminal;
the authentication notification message is constituted by a extensible authentication protocol notification request message.
According to an example of the present invention, in a seventh aspect, this object is for example achieved by an apparatus comprising:
a transmitter configured to transmit, via network entity management procedures, terminal mobility restriction information in the form of at least one additional leaf node being added to a network entity management object.
According to further refinements of the example of the present invention as defined under the above seventh aspect,
the apparatus further comprises an adder configured to add the at least one additional leaf node to the network entity management object.
According to an example of the present invention, in an eighth aspect, this object is for example achieved by an apparatus comprising:
a receiver configured to receive, via network entity management procedures, terminal mobility restriction information in the form of at least one additional leaf node being added to a network entity management object.
According to further refinements of the example of the present invention as defined under the above seventh and eighth aspects,
the additional leaf node is added to a primary subscriber parameters leaf node of the management object;
the additional leaf node comprises at least one of a status field, a tree occurrence field, a format field and an access type field;                the additional leaf node represents a value indicating one of a mobile restriction, a fixed restriction and a nomadic restriction;        
the additional leaf node is added under both a current subscription node and other subscriptions node in the network;
the network entity management object is constituted by a worldwide interoperability for microwave access supplementary management object;
the additional leaf node is further added to at least one of a contractual agreement preference list leaf node and a roaming agreement preference list leaf node;
a second additional leaf node is further added to the additional leaf node of the management object;
the second additional leaf node comprises a mobility restriction and at least one list indicating elements where the mobility restriction is to be applied, the elements being at least one of network access providers, visited network service providers, and base stations;
the network entity management procedures are based on one of an open mobile alliance device management protocol and a technical report 069 protocol;
the apparatus further comprises a judger configured to judge whether an accuracy of the terminal mobility restriction information is insufficient or not, wherein the transmitter or the receiver is further configured to transmit or receive, if the accuracy is judged to be insufficient, prior to another network entry authentication procedure, second terminal mobility restriction information in the form of one text information element of a fixed length in one of a downlink channel descriptor message, a ranging response message, a terminal basic capability response message or a registration response message;
the terminal is constituted by one of a mobile station, a mobile phone, a personal digital assistant, an internet tablet, a laptop, and a customer premises equipment unit;
the access network gateway entity is constituted by at least one of an access network gateway and an access network authenticator;
the serving entity is constituted by an access, authorization, and accounting proximity server.
According to further refinements of the example of the present invention as defined under the above fifth to eighth aspects,
at least one, or more of a transmitter, a generator, a receiver, an adder, a judger and the apparatus is implemented as a chipset or module.
According to an example of the present invention, in a ninth aspect, this object is for example achieved by a system comprising:                an apparatus according to the above fifth aspect; and        an apparatus according to the above sixth aspect;        
or                an apparatus according to the above seventh aspect; and        an apparatus according to the above eighth aspect.        
According to an example of the present invention, in a tenth aspect, this object is for example achieved by a computer program product comprising code sections for performing a method according to any one of the above first to fourth aspects when run on a processing means or module.
According to an example of the present invention, in an eleventh aspect, this object is for example achieved by a data structure comprising:
at least one text information element comprised in an authentication notification message, the at least one text information element constituting terminal mobility restriction information.
According to further refinements of the example of the present invention as defined under the above eleventh aspect,
the at least one text information element is constituted by a type-length-value information element;
the at least one type-length-value information element comprises sub information elements relating to at least one of a restriction type, a list of allowed base stations, a list of prohibited base stations, and an allowed location of the terminal;
the authentication notification message is constituted by a extensible authentication protocol notification request message.
According to an example of the present invention, in a twelfth aspect, this object is for example achieved by a data structure comprising:
at least one additional leaf node being added to a network entity management object, the at least one additional leaf node constituting terminal mobility restriction information.
According to further refinements of the example of the present invention as defined under the above twelfth aspect,
the additional leaf node is added to a primary subscriber parameters leaf node of the management object;
the additional leaf node comprises at least one of a status field, a tree occurrence field, a format field and an access type field;
the additional leaf node represents a value indicating one of a mobile restriction, a fixed restriction and a nomadic restriction;
the additional leaf node is added to both a current subscription leaf node and other subscriptions leaf node in the network;
the network entity management object is constituted by a worldwide interoperability for microwave access supplementary management object;
the additional leaf node is further added to at least one of a contractual agreement preference list leaf node and a roaming agreement preference list leaf node;
a second additional leaf node is further added to the additional leaf node of the management object;
the second additional leaf node comprises a mobility restriction and at least one list indicating elements where the mobility restriction is to be applied, the elements being at least one of network access providers, visited network service providers, and base stations;
second terminal mobility restriction information is constituted by one text information element of a fixed length in one of a downlink channel descriptor message, a ranging response message, a terminal basic capability response message or a registration response message.
Mobility restrictions may be useful e.g. for implementing a ‘home zone’ or other use cases, where the subscriber and device is restricted to a specific area or set of base stations. Also, mobility restrictions may be necessary according to country-specific regulation. This might require a WiMAX network that in general is capable of offering full mobility support for subscribers and WiMAX devices to restrict specific subscribers and devices to a specific area, or restrict mobility in terms of possible handovers between base stations, access networks or even different access technologies (including different radio technologies like WiMAX/WLAN or access according to the 3GPP2 or 3GPP specifications).
In this description, the term “SS” is used to refer to the subscriber station, also named as mobile station (MS) or terminal. It can be a mobile device like a mobile phone, personal digital assistant (PDA), internet tablet, laptop, customer premises equipment (CPE) unit or similar type of device. SS also includes the fact that information passed to the SS may sometimes be shown to the subscriber/user.
Potential types of information that are considered beneficial for the SS when either entering the network or already being connected to the network, include:
The fact that the network only offers limited mobility support;
The type of mobility restrictions which apply
Information whether handover (HO) to other base stations (BSs) is allowed or not, or whether MS initiated HO is prohibited;
Information about an allowed region (like geodetic or civic location information about an area where access for this SS is allowed);
Information about a set of base stations that are allowed to be accessed (so-called “whitelist”) or not allowed (so-called “blacklist”).
Information provided to the SS can be related to a mobility restriction applying to a whole network or network segment, to individual SSs or a group of SSs. This can, e.g., be based on an individual subscription, or e.g. on the actual network operator information (‘home network’) of a roaming SS (i.e. specific mobility restrictions applying to all subscribers of a specific roaming partner's network only).
In this connection, examples of the present invention enable one or more of the following:
Providing appropriate information to the SS;
Improving the implementation of mobility restrictions in WiMAX networks;
Improving existing solutions for all related work in the WiMAX area;
Enabling informing a roaming subscriber about the roaming visited/access network being one with mobility restrictions;
Avoiding useless network entry attempts from those SSs that are not permitted at the BS at stake, according the network's mobility restrictions;
Avoiding unnecessary MS initiated handover preparation or execution attempts;
Improving user experience for the SS/subscriber;
Enabling efficient network operation with avoiding a potentially large number of unnecessary denied handover or network entry attempts due to the fact that the SS is not aware of the information required to judge whether the current network enforces mobility restrictions and whether such operation like a handover can succeed or not.